Well i had always been atracted by the iphone GPU a few years ago, but lately not really.
Its cool that they have 64bit cpus, and its cool they finally have a larger screen and a new design.
Its really a great phone overall but... i cant stand the IOS restrictions and itunes crap.
And regarding the GPU its not something to brag about, taking in account the price, i mean, my 300€ nexus 5 (with the "old" snapdragon 800) in 3dMark gets already 16k in icestorm unlimited and my nvidia shield tablet (Tegra K1 wich is a real beast) gets 32k.
Benchmarks are not everything, i know but, they give you a good glance of the device performance, and tbh im not really impressed with this A8 chip.
The Tegra K1 32bits smokes everything atm, and the upcoming tegra k1 (64bit) will be a real monster in the nexus tablet.